According to multiple sources, Junior Seau, 43-year-old ex-pro football star was found dead at his Oceanside, California beachfront home.

He supposedly died of a self-inflicted gunshot wound to the chest.

Details are still coming out but there are several possible theories as to why he did this.

Back near the end of 2010 he was arrested on suspicion of spousal assault with injury against his 25-year-old live in girlfriend.

Shortly after, he "fell asleep" and his car drove off a cliff. He survived with only minor injuries.

So it's possible he was already suicidal.

Another theory comes from the fact that many ex-NFL players have committed suicide due to concussion induced dementia and other degenerative brain conditions caused by too many impacts to the head.

Dave Duerson, another ex-football player, committed suicide with a gunshot wound to the chest specifically so his brain could be studied afterwards.

It turned out to be C.T.E. (chronic traumatic encephalopathy) which is caused by multiple blows to the head.

A doctor studying C.T.E. said:

"When it comes to suicide and chronic traumatic encephalopathy, it is possible that in some individuals the combination of C.T.E.-related symptoms of poor impulse control, depression and cognitive impairment may indeed lead to suicide."

Regardless of the reason, it's so sad that things ended this way for Junior, who will be missed by not only his family and friends but by fans everywhere.